package com.donkey.test;


/**
 * Created by luo on 2017/9/27.
 */
public class LocationUtils {

    private static double EARTH_RADIUS = 6378.137;

    private static double rad(double d) {
        return d * Math.PI / 180.0;
    }

    /**
     * 通过经纬度获取距离(单位：米)
     * @param lat1
     * @param lng1
     * @param lat2
     * @param lng2
     * @return
     */
    public static double getDistance(double lat1, double lng1, double lat2,
                                     double lng2) {
        double radLat1 = rad(lat1);
        double radLat2 = rad(lat2);
        double a = radLat1 - radLat2;
        double b = rad(lng1) - rad(lng2);
        double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a / 2), 2)
                + Math.cos(radLat1) * Math.cos(radLat2)
                * Math.pow(Math.sin(b / 2), 2)));
        s = s * EARTH_RADIUS;
        s = Math.round(s * 10000d) / 10000d;
        s = s*1000;
        return s;
    }

    public static void main(String[] args) {
        System.out.println("distance: " + getDistance(24.273634, 118.071415, 24.273634, 118.071415));
        System.out.println("distance: " + getDistance(24.273634, 118.071415, 24.273634, 118.061415));
        System.out.println("distance: " + getDistance(24.273634, 118.071415, 24.263634, 118.071415));
        System.out.println("distance: " + getDistance(24.273634, 118.071415, 24.263634, 118.061415));
        System.out.println("distance: " + getDistance(24.273634, 118.071415, 24.283634, 118.081415));
        System.out.println("distance: " + getDistance(24.273634, 118.071415, 24.253634, 118.051415));
        System.out.println("distance: " + getDistance(24.273634, 118.071415, 24.273634, 118.091415));
        System.out.println("distance: " + getDistance(24.273634, 118.071415, 24.293634, 118.071415));
        System.out.println("distance: " + getDistance(24.273634, 118.071415, 24.293634, 118.091415));

        System.out.println("distance: " + getDistance(24.273634, 118.071415, 24.273634, 118.041415));
        System.out.println("distance: " + getDistance(24.273634, 118.071415, 24.243634, 118.071415));

        System.out.println("distance: " + getDistance(24.273634, 118.071415, 24.273634, 118.031415));
        System.out.println("distance: " + getDistance(24.273634, 118.071415, 24.233634, 118.071415));

        System.out.println("distance: " + getDistance(24.273634, 118.071415, 24.273634, 118.021415));
        System.out.println("distance: " + getDistance(24.273634, 118.071415, 24.223634, 118.071415));

        System.out.println("distance: " + getDistance(24.48923061, 118.10388605, 24.47923061, 118.11388605));

        // 0.01 约相当于 1000m
    }
}
